Multi Channel Device for Directional Shaping of Electric Fields e.g., Tumor Treating Fields (TTFields)

Abstract

The paths that alternating electric fields take through a body part can be controlled by providing at least eight electrically isolated signal generators, each of which is configured to apply electrical signals between a respective electrode element on one side of the target region and a respective electrode element on the opposite side of the target region. This replaces the prior art's single wide-cross-section electric field with eight independently controllable electric fields, each of which has a relatively narrow cross-section. Using these relatively narrow cross-section fields, either alone or in combination, can improve aiming of the electric field, which can in turn increase the field strength in the target region. Optionally, activation of these relatively narrow cross-section fields can be shifted in time to achieve steering of the overall electric field.

What is claimed is: 
     
         1 . An apparatus for applying an electric field to a target region using at least eight first electrode elements positioned on a first side of the target region and at least eight second electrode elements positioned on a second side of the target region that is opposite to the first side of the target region, the apparatus comprising:
 at least eight electrically isolated first signal generators, wherein each of the first signal generators has a respective first control input, and wherein each of the first signal generators is configured to, in response to a respective first control signal that arrives at the respective first control input, apply an electrical signal between a respective one of the at least eight first electrode elements and a respective one of the at least eight second electrode elements; and   a controller that is programmed to generate each of the first control signals.   
     
     
         2 . The apparatus of  claim 1 , wherein each of the first signal generators is configured to, (a) in response to a respective first control signal that arrives at the respective first control input, apply a positive electrical signal between the respective one of the at least eight first electrode elements and the respective one of the at least eight second electrode elements, and (b) in response to a respective second control signal that arrives at the respective second control input, apply a negative electrical signal between the respective one of the at least eight first electrode elements and the respective one of the at least eight second electrode elements. 
     
     
         3 . The apparatus of  claim 2 , wherein the controller is further programmed to, for each of the first signal generators, apply the respective first control signal and the respective second control signal at respective times in an alternating sequence so that the respective first signal generator will generate an output that alternates between a positive electrical signal and a negative electrical signal. 
     
     
         4 . The apparatus of  claim 3 , wherein the controller is further programmed to interpose a break in time between each first control signal and each second control signal. 
     
     
         5 . The apparatus of  claim 1 , wherein the controller is further programmed to generate each of the first control signals in a sequence that causes each of the at least eight first signal generators to generate an output with a given waveform, wherein the output of each of the at least eight first signal generators is shifted in time with respect to an output of at least one other first signal generator. 
     
     
         6 . The apparatus of  claim 5 , wherein the controller is further programmed to control the shifting in time to steer an electric field within the target region. 
     
     
         7 . The apparatus of  claim 5 , wherein the controller is further programmed to generate each of the first control signals in a sequence that causes each of the at least eight first signal generators to generate an output that alternates between a positive electrical signal and a negative electrical signal. 
     
     
         8 . The apparatus of  claim 1 , further comprising:
 the at least eight first electrode elements; and   the at least eight second electrode elements.   
     
     
         9 . The apparatus of  claim 1 , further comprising:
 at least eight electrically isolated second signal generators, wherein each of the second signal generators has a respective second control input, and wherein each of the second signal generators is configured to, in response to a respective second control signal that arrives at the respective second control input, apply an electrical signal between a respective one of at least eight third electrode elements and a respective one of at least eight fourth electrode elements,   wherein the controller is further programmed to generate each of the second control signals.   
     
     
         10 . The apparatus of  claim 9 , wherein the controller is further programmed to generate each of the first control signals in a sequence that causes each of the at least eight first signal generators to generate an output with a first given waveform, wherein the output of each of the at least eight first signal generators is shifted in time with respect to an output of at least one other first signal generator, and
 wherein the controller is further programmed to generate each of the second control signals in a sequence that causes each of the at least eight second signal generators to generate an output with a second given waveform, wherein the output of each of the at least eight second signal generators is shifted in time with respect to an output of at least one other second signal generator.   
     
     
         11 . A method for applying an electric field to a target region using at least eight first electrode elements positioned on a first side of the target region and at least eight second electrode elements positioned on a second side of the target region that is opposite to the first side of the target region, the method comprising:
 applying respective first electrical signals between respective ones of the at least eight first electrode elements and respective ones of the at least eight second electrode elements, wherein the first electrical signals all have a given first waveform, wherein each of the first electrical signals is shifted in time with respect to at least one other first electrical signal, and wherein each of the first electrical signals is electrically isolated from all other first electrical signals.   
     
     
         12 . The method of  claim 11 , wherein the first electrical signals are applied shifted in time to steer an electric field within the target region. 
     
     
         13 . The method of  claim 12 , wherein each of the first electrical signals alternates between a positive polarity and a negative polarity. 
     
     
         14 . The method of  claim 11 , further comprising:
 positioning the at least eight first electrode elements on the first side of the target region; and   positioning the at least eight second electrode elements on the second side of the target region.   
     
     
         15 . The method of  claim 11 , further comprising:
 applying respective second electrical signals between respective ones of at least eight third electrode elements and respective ones of at least eight fourth electrode elements, wherein the second electrical signals all have a given second waveform, wherein each of the second electrical signals is shifted in time with respect to at least one other second electrical signal, and wherein each of the second electrical signals is electrically isolated from all other second electrical signals.   
     
     
         16 . The method of  claim 15 , wherein the first electrical signals are applied shifted in time to steer an electric field within the target region, and
 wherein the second electrical signals are applied shifted in time to steer an electric field within the target region.   
     
     
         17 . The method of  claim 16 , wherein each of the first electrical signals alternates between a positive polarity and a negative polarity, and
 wherein each of the second electrical signals alternates between a positive polarity and a negative polarity.